Do I get it right, that the "twitter" cards is just some meta markup, that can be included in Octave's Newsfeed? This might not be a big deal. But what is the benefit of this effort (explained to a non-Twitter-user like me)? This is not clear to me from the url .
Thanks for explaining. What I do like about your idea is the "The Open Graph protocol" part (the "og:" tags) for providing rich meta data for any social network (not only twitter). This really seems to be an open "standard" developed by Facebook (at least I found no license information) and is widely adapted in social media.
When I have some time, as a start I can think about adapting the "og:" portion. This should not be too hard and maybe you can report back if this already sufficient for twitter.